SHANK3 and Anxiety: Here we reveal (1) that anxiety, deficits in sociability, and social novelty recognition are present in Shank3−/− mice as early as 3 weeks of age, (2) that the development of anxiety, repetitive behaviours, sociability, and social novelty recognition behaviours can not only be prevented if zinc supplementation is initiated from the beginning of brain development, but moreover are sustained into adulthood long after the exposure to zinc supplementation had ceased.